Medical devices are frequently used to treat the anatomy of patients. Examples of such devices include stents, grafts, stent-grafts, filters, valves, occluders, markers, mapping devices, therapeutic agent delivery devices, prostheses, pumps, bandages, and the like. Such devices can be implanted. Such devices can also be expandable and delivered endoluminally. In the latter case, an expandable device, is constrained by a constraining member, such as a sheath or a sleeve, toward a reduced delivery profile suitable for endoluminal delivery on a catheter, introduced into the body at an insertion point, delivered endoluminally toward a treatment site, and expanded at the treatment site.
Although many improvements have been made to medical device assemblies in general, constraining members, configured with sufficient strength to constrain expandable devices, can reduce the flexibility and increase the profile of devices due to the thickness of the materials used. Conversely, thinner walled constraining members can rip apart at stitch lines. Constraining members can burst when used to constrain self-expanding devices to very small delivery profiles.
Therefore, smaller profile medical device assemblies that can be reliably introduced and moved through body conduits such as the vasculature are desired. In particular, thinner and stronger constraining members for use with expandable medical devices are desired.